The Frasers are among the growing number of wise home buyers that have their houses inspected before purchase.

"It's consumer awareness," said Vera Hollander, spokeswoman for the American Society of Home Inspectors (ASHI). "Home inspections took off in the '80s, when the prices of homes skyrocketed. Every dollar, every dime you put into your house is critical."

With the median US home hovering around $116,000, and 30 years of mortgage payments ahead, it's a wise investment.

While most banks require inspections for dry rot and wood-hungry critters such as termites, complete home inspections are optional in most states. Only slightly more than 40 percent of buyers get them, according to ASHI.

"You want to be an informed consumer. You should be at least informed of what you're buying, when you're buying a home," says Craig Walz, owner of Total Home Inspection Services in Oregon.

Trained inspectors can spot potential defects that will help the buyer estimate repair costs, renegotiate the price, or cancel the deal, according to Kathleen Howlett, information/education director for the board. Inspectors can also point out the positive aspects of the house, and any maintenance that will be required.

Buyers should check out prospective home inspectors. The State of Oregon Construction Contractor's Board, a consumer protection agency, has seen an increased number of claims filed against inspectors who find "flaws" and offer to fix them. Or those who dream up flaws to give the buyer leverage to knock down the price of a home.

Five years ago, Oregon began registering home inspectors, requiring them to have at least a $2,000 bond. Some states have few requirements; some, more stringent. (See story, below.)

The most common home inspection is for wood damage caused by dry rot or insects. This inspection is usually required by mortgage lenders. The average cost: $75 and up. Some lenders also may require a roof inspection. The average cost: $50.

Specialty inspections include a structural examination, for the soundness of a concrete or fieldstone foundation, a geological inspection for a house built on potentially unstable ground.

A total home inspection usually includes the home's heating, cooling, and electrical systems, plumbing, roof, attic, visible insulation, walls, ceilings, floors, windows, doors, and appliances. The average cost: $250 and up.

"We're not an expert in every field. We're more of home generalists," Mr. Walz says, adding that inspectors usually have a residential construction background. "We know a little bit of all the components in the home. If we find a problem, then we defer to specialists."

The inspector the Frasers hired had some concerns about crumbling concrete along a basement window and recommended that they consult a structural engineer to evaluate it.

Home inspections are not foolproof. "We are limited to areas of the home that are accessible," Walz says. That means they can't look under carpet or see through walls. "We don't move furniture. We can't assume that liability," Walz says.

A home inspection can also alert the seller to potential problems that may affect a home's value or salability. If the defect is discovered after a purchase offer has been signed, there may not be enough time to fix it before the buyer backs out.

"I've seen it happen many times. The deal falls apart because it took months to correct the problem. They could have had it corrected beforehand," Walz says. But buyers shouldn't rely on an inspection commissioned by the seller.

"We recommend that the buyer get his own inspection," says Ms. Howlett, of Oregon's Construction Contractors Board. "If the buyer is unhappy with a home inspector, the buyer can file a claim with us. But they can only file a claim if they have contract with the home inspector."

If the seller obtained the inspection, the seller has no interest in filing a claim for a faulty inspection on a house they no longer own.

The Frasers were satisfied with their home inspection. The crumbling concrete was not enough to be concerned about. They closed on the house and are resting a little easier.